import Vue from 'vue'
import VueRouter from 'vue-router'
import Login from '../views/Login.vue'
import Home from '../views/Home.vue'
import Welcome from '../views/Welcome.vue'
Vue.use(VueRouter)

const routes = [
  { path: '/', redirect: 'login' },
  { path: '/login', component: Login },
  {
    path: '/home',
    component: Home,
    redirect: '/welcome',
    children: [
      { path: '/welcome', component: Welcome }
    ]
  }
  // {
  //   path: '/',
  //   name: 'Home',
  //   component: Home
  // },
  // {
  //   path: '/about',
  //   name: 'About',
  //   // route level code-splitting
  //   // this generates a separate chunk (about.[hash].js) for this route
  //   // which is lazy-loaded when the route is visited.
  //   component: () => import(/* webpackChunkName: "about" */ '../views/About.vue')
  // }
]
const router = new VueRouter({
  routes
})
// 所有的路由跳转时都会经过这个前置守卫函数的处理
// 场景：一些有权限的组件需要经过验证
// 导航守卫只能判断token是否存在，不能判断token是否合法
router.beforeEach((to, from, next) => {
  if (to.path === '/login') {
    return next()
  } else {
    const tokenStr = sessionStorage.getItem('token')
    if (!tokenStr) return next('/login')
    next()
  }
})
export default router
